An electrical switch box typically has what is referred to as "ears" which are adjustably secured to the outer ends of the box and mount screw holes for fastening the box to other structure. The ears are secured by either one or two screws and are referred to as one screw ears as illustrated in FIG. 1 or two screw ears as illustrated in FIG. 2. Generally, one screw eared switch boxes are primarily designed for receiving either so-called Romex cable, i.e. plastic covered wire, or the so-called BX cable, a flexible metal sheathed cable. Two screw eared electrical switch boxes are generally designed for receiving and being secured to rigid pipe enclosing the wiring.
In applicant's prior U.S. Pat. No. 4,561,615 entitled "Bracket For Junction Box", a substantially improved electrical switch box is disclosed. However, while representing a substantial improvement with respect to mounting of one screw ear boxes, the bracket of the subject patent was not adapted to the two screw ear type switch boxes. Thus, there is a demand for a still further improved switch box mounting bracket adapted for positioning and securing either a one screw eared switch box or a two screw eared switch box.
Experience with the switch box mounting bracket of applicant's prior patent has also indicated a need for further improvement with regard to providing an electrical switch box bracket which can be mounted in any of several positions and which includes a stiffening leg for stiffening the overall bracket after installation. Additionally, it has been recognized that it would be advantageous to provide a further improved electrical switch box mounting bracket such that a pair of such brackets could be mounted on opposite sides of a metal stud to form a double mounting arrangement. Metal studs are currently being used in new building construction in large quantities. Thus even minor improvements in electrical switch boxes have important implications in the trade with respect to the mounting of such brackets on metal studs.
In another respect the conventional switch box mounting bracket has not adapted to being mounted in pairs, i.e., on the same side of the stud, attached together and forming a piggyback arrangement. Another need has been for an improved electrical switch box adapted to be associated with an extension plate enabling the bracket to be mounted at some location between the studs as distinct from being secured to one of the studs.
In U.S. Pat. No. 4,533,060 there is disclosed an improved mounting bracket for a square outlet box on which a dry wall ring is typically mounted. This patent recognizes the advantage of having offsets on the face of the bracket to minimize bulging after the typical sheet rock dry wall is secured to the studs and covers the mounting bracket except for that portion purposely left exposed for purposes of making connections. This patent also teaches the advantage of using a stiffening arm as part of the bracket for mounting of electrical outlet and junction boxes. However, because of different structural considerations, the advantage of using offsets and a stiffening arm has not been carried over into the construction of brackets for mounting electrical switch boxes as contrasted to mounting electrical outlet and junction boxes. Thus, the present invention has as one object providing an improved electrical switch box mounting bracket which in one embodiment provides both offsets on the surface of the bracket and a stiffening arm.
A further improved mounting bracket for electrical outlet boxes is disclosed in U.S. Pat. No. 4,572,391. This latter patent provides a bracket for mounting pairs of electrical outlet boxes and takes advantage of the offset arrangement and stiffening arm arrangement taught by the previously referred to U.S. Pat. No. 4,533,060. Additionally, U.S. Pat. No. 4,572,391 teaches an extension plate construction enabling the outlet box bracket to be mounted at some location between the studs rather than being secured to a selected stud. Additionally, U.S. Pat. No. 4,572,391 teaches an outlet box mounting bracket adapted to being mounted in pairs in a piggyback fashion. However, the provision of an electrical switchbox mounting bracket as contrasted to an outlet box mounting bracket adapted for use with an extension plate and for being mounted in pairs in piggy-back fashion has not appeared in the market prior to the present invention. Providing such a switch box mounting bracket is another object of the invention. The present invention also seeks to take advantage of providing in a switch box mounting bracket the offset features, the stiffening arm features and the extension bracket features as disclosed for an outlet box mounting bracket in U.S. Pat. No. 4,603,789 entitled "Extension Bracket for Mounting Electrical Outlet Box".
In another aspect of the prior art, U.S. Pat. No. 1,620,063 teaches a switch box mounting bracket utilizing a tab as a means of securing a switch box to a bracket. However, the bracket in such patent lacks a stiffening arm, offsets, the ability to piggyback, the ability to mount a pair of the brackets on opposite sides of the stud and the ability to extend the bracket to a location between the studs. Furthermore, the disclosed switch box mounting bracket was designed to be fastened to wood studding and would not be useful for the modern type of dry wall construction because of the bulging the bracket would cause.